Environmental, personal hygiene key to prevention of Lassa Fever
The Minister of Health, Prof. Isaac Adewole, recently announced that 15 states have been hit by an outbreak of Lassa fever, with 105 laboratory-confirmed cases, three probable cases and 31 deaths.The 15 states are Bauchi, Plateau, Taraba, Nasarawa, Benue, Kogi, Ebonyi, Rivers, Imo, Anambra, Edo, Delta, Ondo, Osun and Lagos.Since 2015, more than 10 healthcare workers have been infected with the Lassa fever virus. Two out of them died.
In May 2016, eight states reported Lassa fever cases. Currently, 248 contacts are being followed up in the country. The other 15 previously affected states have completed the 42-day period following last known possible transmission.In the face of the recent outbreak, health experts have advised that families, communities and individuals should be more hygienic about their surroundings and the food they eat.
Consultant virologist at the College of Medicine, Lagos, Prof. Sunday Aremu Omilabu, said Lassa fever is a severe and often-fatal hemorrhagic illness caused by Lassa virus. Since it was original discovered in 1969 in the village of Lassa in Borno State, there have been countless outbreaks of various magnitude and severity across West Africa.
The Lassa virus is a member of the Arenaviridae virus family. Humans contract the virus primarily through contact with the contaminated excreta of Mastomys natalensis rodents commonly known as the multimammate rats, which are the natural reservoirs for the virus. Omilabu said: “The rodents live in bushes, but because of dry season, they run to houses for protection and live with humans and deposit excreta on floors, tables, beds and foods.
“The foods that can be contaminated by the rodents include, garri, yam, rice and beans, among others. So, people should cover their foods properly, avoid taking soaked garri that was not covered. While feeding on the foods, the rodents defecate and urinate on them, which is not good for human consumption. So, people should not eat leftover foods without properly warming them.
“The virus is transmitted to humans through cuts and scratches. In some regions, mastomys rodents are consumed as foods, but it is better for people to avoid contact with rodents. Secondary transmission of the virus between humans occurs through direct contact with infected blood or bodily secretions. “This occurs mainly between individuals caring for sick patients, although anyone who comes into close contact with a person carrying the virus is at risk of infection. Nosocomial transmission that occurs as a result of treatment in a hospital and outbreaks in healthcare facilities in endemic areas represents a significant burden on the healthcare system.”
“In the early stages, Lassa fever is often misdiagnosed as influenza, typhoid or malaria, and as a result many patients fail to receive appropriate medical treatment. Making a correct diagnosis of Lassa fever is made difficult by the wide spectrum of clinical effects that manifest, ranging from asymptomatic to multi-organ system failure and death. The onset of the illness is typically indolent, with no specific symptoms to distinguish it from other febrile illnesses.”
Omilabu explained that signs and symptoms of Lassa fever include fever, headache and general malaise, followed by a sore throat, nausea, vomiting, abdominal pain and diarrhoea in some cases.He said: “After four to seven days, many patients will start to feel better, but a small minority will proceed to display such symptoms as edema, hypertension, bleeding and shock. Death from Lassa fever most commonly occurs 10 to 14 days after symptom onset, if it is not properly handled.
“The impact of the disease in endemic regions of West Africa is immense, and therefore, means to diagnose, treat and prevent this viral hemorrhagic fever will provide a significant public health benefit. Suspected cases should be reported to hospitals for proper medical tests and treatments.
“One of the hallmarks of Lassa virus infection is the apparent absence of functional antibodies during acute infection. A fundamental understanding of the mechanisms of antibody-mediated neutralisation of Lassa virus may have significant implications for the generation of antibody-based therapeutics or epitope-targeted vaccines.
“Confirmed incidences have been recorded in Sierra Leone, Liberia, Guinea, Nigeria and Mali. However, concerns exist that there may be Lassa viruses in such other countries as Central African Republic, Ghana, Mali, Ivory Coast, Togo, Benin and Cameroon.
“Furthermore, Mastomys rodents are distributed across the African continent, indicating a strong possibility for the spread of the disease they carry.”Dr. Omojowolo Olubunmi a consultant neurologist and chairman, Nigeria Medical Association (NMA) Lagos State chapter, said about 80 per cent of human infections are without symptoms. The remaining cases have severe multiple organ disease, where the virus affects several organs in the body, such as the liver, spleen and kidneys. Lassa fever is a significant cause of severe illness and death.
Olubunmi explained that prevention of Lassa fever relies on promoting good community hygiene to discourage rodents from entering homes. Effective measures include storing grain and other foodstuffs in rodent-proof containers, disposing of garbage far from the home and maintaining clean households.He said: “In healthcare settings, prevention is by standard precautions, where all blood and body fluids are considered potentially infectious. Standard precautions are applied to all patients at all times and in all health care settings. These include hand hygiene, use of appropriate personal protective equipment (PPE), waste disposal, cleaning and disinfection of medical equipment and environment, safe injection practices.”
Also, the former president, Association of Resident Doctor, Lagos University Teaching Hospital (LUTH), Dr. Adebayo Sekunmade, said: “The symptomatology includes fever, weakness and malaise, muscle pain, which mimics other infections like malaria and typhoid fever in the mild form of the disease. However, in the serious form, which occurs in only 20 per cent of patients, bleeding from the gums, anus and vagina occurs in addition to diarrhoea, vomiting and deafness, among others”. He said: “Infected patients should be isolated, while health workers should ensure standard infection prevention and control protocols, which is universal precaution as well as barrier nursing.
“Treatment is supportive to ensure patient is not dehydrated. It also includes correction of electrolyte imbalance and treatment for other symptoms. Use of ribavirin is important in the early stages of the disease to prevent its progression.”Dr. Ezekiel Sofela Oridota, a senior lecturer and consultant, Public Health Physician, Epidemiology and Biostatistics Unit, Department of Community health and Primary care, College of Medicine, University of Lagos and Lagos University Teaching Hospital Lagos said Lassa fever increases during the dry season, as the rodents stay in the bush during raining season.
He said: “Government should promote health education among the people by creating radio and television jingles, including other materials to educate people on what to do to avoid Lassa fever infections. It is important to let people know the importance of visiting hospital whenever they have symptoms.“We need to increase and strengthen our surveillance, as some disease outbreaks we’ve had was as a result of poverty and ignorance.“Pregnant women should be conscious of their health and of their unborn babies, as they are more at risk of having Lassa fever due to their low immunity. “People should stop open defecation and make sure that their environments are clean to avoid being affected.”
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